Abstract: Abstract:Objective
To observe the changes of neuronal apoptosis  and expression levels of  Caspase-9  in hippocampus and amygdala of posttraumatic stress disorder(PTSD)  rats,and to disscus the mechanism of the volume abnormalities of hippocampus and amygdala. Methods 100 male Wistar rats were divided into control group (n=20) and PTSD group (n=80). The PTSD rat model was produced by giving the rats single-prolonged stresS followed a single inescapable electric foot shock (SPS & S). The behavior changes of rats were examined using Morris water maze test and freezing behavior test. The positive apoptotic rates of  cells and apoptotic rates in hippocampus and amygdalawere detected by TUNEL-staining and  flow  cytometry (FCM). The expression level of Caspase-9 was detected by Western blotting method. Results The excape latency (EL) time and percentage of freezing behavior in PTSD group were higher than those in  control group (P<0.05). The percentages of TUNEL-positive cells and the apoptotic  rates in hippocampus and amygdala of PTSD  1,4,7 and 14 d rats were higher than those in control group (P<0.05),but there was no significant difference between PTSD 28 d rats and control rats (P>0.05). The expression levels of Caspase-9 in hippocampus and amygdala of  PTSD 1,4,7 and 14 d rats were higher than those in control group(P<0.05). Conclusion The apoptosis of neurons and expression levels of Caspase-9 in hippocampus and amygdala  of PTSD rats are increased,which indicates that apoptosis may be duced to the volume abnormalities of hippocampus and amygdala of PTSD.

Key words: posttraumatic stress disorder, hippocampus, amygdala, apoptosis